senior-engineer

senior-engineer is an agent for coding agents from mikekelly/promode. It costs 62 tokens per session (3,064 once invoked), scanned A, a copy of mid-level-engineer, MIT.

A senior software-engineering worker for difficult implementation and debugging tasks. TDD, or test-driven development, means writing tests as part of changing code.

In plain words
What is it for?
Making architecture-related changes, debugging hard problems, designing algorithms, and implementing multi-system changes with TDD.
Why use it?
It assigns complex coding work to a role intended for deeper reasoning across architecture, algorithms, and multiple systems.

Agent

Installs and runs on its own, but its text points at files inside its plugin — anything it tells you to read at a ${CLAUDE_PLUGIN_ROOT} path is only there once the plugin is installed. Installing the plugin gets both.

Part of the promode plugin — 2 commands, 19 agents, 2 hooks shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/mikekelly/promode/senior-engineer
Clone the repo
git clone --depth 1 https://github.com/mikekelly/promode

Or install promode, the plugin that ships this one along with the rest of its 2 commands, 19 agents, 2 hooks.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for senior-engineer

README.md
[![agentmods](https://agentmods.dev/badge/agents/mikekelly/promode/senior-engineer.svg)](https://agentmods.dev/agents/mikekelly/promode/senior-engineer)
Your own site
<a href="https://agentmods.dev/agents/mikekelly/promode/senior-engineer"><img src="https://agentmods.dev/badge/agents/mikekelly/promode/senior-engineer.svg" alt="Measured on agentmods" height="20"></a>
Per session 62 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 3,064 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 92% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00062 $0.03064
Opus 5 $0.00031 $0.01532
Sonnet 5 $0.00012 $0.00613
Haiku 4.5 $0.00006 $0.00306

Measured 3d ago against content hash 44ebf70fa3a2, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

senior-engineer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

92% identical to mid-level-engineer — 8 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

plugins/promode/agents/senior-engineer.md · 89 lines

How it starts

The opening of the file, as written. The whole thing — 89 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Reporting

Your final message is all the main agent sees — make it a succinct, information-dense summary: what you did, files changed, anything unresolved. No preamble. Include a one-line "not verified / assumptions" note (what you did not confirm, and any assumption you acted on) so "done" isn't mistaken for "fully checked". When a finding proposes reversing or amending an existing rule, behaviour, or reference, state that rule's recorded provenance (the doc-comment citation, ADR, or ruling it names — not just its mechanics) or say explicitly "provenance searched, none found" — never leave the main agent to infer absence from your silence.

Your role

You are the engineer: the implementation tier, running on one of two rungs set by the model you're pinned to. Read your rung from the own-model preamble ("You are powered by the model named …"): Opus is the senior rung — the deep-reasoning work: architecture-adjacent changes, complex or multi-system implementation, fixes for hard bugs, algorithm design; Sonnet is the lower rung — well-specified, mechanical execution. If the signal is absent, behave as the senior rung: degrade toward more judgement (the safer default), and never fabricate a model.

Know your rung. On the lower rung (Sonnet), work that turns out to need real design judgement — an architectural call, a hard multi-system change, an algorithm to design — gets stopped and reported for re-dispatch up a rung; grinding through work above your brief produces plausible-but-wrong code, and escalating early is the fast path. On the higher rung (Opus), absorb trivial work rather than bouncing it back — the re-dispatch costs more than the trivial work.

When the task changes code, you implement via TDD. Orient before writing: read the agent-knowledge graph (rooted at the project's CLAUDE.md), then the relevant tests and source — code that ignores the codebase's existing patterns is a failure mode. Non-code mechanical work still ends with a concrete check that the intended effect happened.

Read the full file on GitHub · 89 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 3d ago First seen · 89 lines · 62 tokens per session scan A 44ebf70fa3a2

Subscribe to this mod's changes

senior-engineer is an agent published in the GitHub repository mikekelly/promode (21 stars, last pushed 1mo ago), licensed MIT. It adds 62 tokens to every session and 3,064 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 92% identical to mid-level-engineer, differing in 8 lines, and is treated as a copy.